Evaluation of the Efficacy and Side Effects of Silymarin Alone and in Combination with Alendronate in the Treatment of Postmenopausal Osteoporosis: A Pilot Study

Abstract

This is the first study to be done on postmenopausal females in order to evaluate the clinical outcome of combination therapy of silymarin and alendronate in treatment of postmenopausal osteoporosis compared to the monotherapy of each. Drugs derived from natural products are known to have fewer side effects than pharmaceutical drugs and so it was of significance to develop natural alternative therapies for preventing postmenopausal or senile osteoporosis. Numerous studies have shown that natural products and dietary components such as Silymarin have positive effects on bone remodeling particularly by inhibiting bone resorption. The present study is an early attempt to measure the effect of silymarin on postmenopausal osteoporotic women. In total, 75 patients with postmenopausal osteoporosis were included only 69 of them completed the study. The population of the study was categorized into three groups: group 1 (n=22) where patients received 70 mg Alendronate once weekly for two years, group 2 (n=23) where patients received 140 mg Silymarin three times daily for two years and group 3 (n=24) where patients received 35 mg Alendronate once weekly and 140 mg Silymarin three times daily for two years. Then DXA scans were done after one year of treatment and after two years of treatment. Although the results in the silymarin group are significantly less than in alendronate group and combined therapy group yet they are promising as the patients received silymarin showed improvement in the mean T-scores of spine, femur and wrist where the P-values when comparing the percentage change of T-scores of the three groups after two years of treatment are as follows (pspine=0.000, pfemur=0.000, pwrist=0.033). Compliance to silymarin therapy was good as the drug is palatable and has no gastric side effects as compared to the known side effects of alendronate therapy. Combining both Silymarin and alendronate therapy yielded better results than treatment with Silymarin alone yet these results do not conclude the synergestic effect of the combination as previous studies have shown improvement of bone mineral density in patients receiving 35 mg weekly dose of alendronate (Marjorie et al., 2003). Another study Summary and conclusion 87 comparing two patient groups , one receiving 35mg weekly alendronate and another group receiving 35mg weekly alendronate combined with Silymarin is necessary to prove this hypothesis. On the contrary this study is a very short term study and has been conducted on a limited group of patients. Although we tried to consider patient variables such as age, weight, and race yet a lot of other factors could possibly affect the outcome as number of pregnancies, genetic factors, level of activity and exposure to sunlight. To reach a conclusion that silymarin is an efficient drug to treat postmenopausal osteoporosis requires further studies with longer time frames, dose assessment and larger patient groups with assessment of patients variables like bone turnover markers, liver functions, kidney functions and thyroid functions.